Typically, telecommunication systems that provide broadband access to customers contain a communication, digital subscriber line (DSL), or residential gateway which consists of an xDSL (any type of digital subscriber line) modem or xPON (any type of passive optical network) interface combined with various local area networking (LAN) technologies to enable sharing the broadband access with other computers or devices within the building or residence. Wireless local area network standards and home phone line networking (HPNA) are examples of LAN technologies. In addition, some telecommunication systems may provide a voice-over-internet-protocol (VOIP) feature to allow telephone calls via the broadband link. Some systems may, in addition to broadband access sharing, need to distribute broadband media content such as video streams into various locations within the residence.
Typically the residential gateway is located inside the house. However, it is desirable to locate the residential gateway at the Network Interface Device (NID) outside the house. A NID is the point of demarcation between the Unbundled Network Element (UNE) loop and the end user's inside wire. Reasons for desirability of locating the residential gateway at the NID include the ability to provide simplified installation wiring and to eliminate the need to have the user home when the bulk of installation occurs. Further, as fiber to the neighborhood rolls out, integration will be easier if the active electronics are already present at the NID. Also, installation practices can be merged between xPON and xDSL systems such that the primary network termination is the merely difference.
However, a significant problem in trying to locate the residential gateway at the NID is the problem of providing power. There is often no source of Alternating Current (AC) power accessible at the NID location. Consequently, powering from inside the house is one viable option. The use of existing phone wiring would be the most desirable way, since the cost of installing new wiring is prohibitive.
However, the existing phone wiring if used for powering the NID must not damage phones devices connected to the phone wiring. Also, if a telecommunication system offers phone service via a broadband link, then the system must have a back up power unit to ensure the availability of lifeline functionality such as 911 calling in the event of a power outage. Furthermore, the existing phone wire must be reserved for voice band telephony including its requisite Direct Current (DC) signaling. This constraint appears to preclude its use for supplying power to the NID.